Pump or motor



Jan. 18, 1927. V1,"615,14o

W. J. RUSDELL.v

PUMP OR MOTOR Filed Jan. lO. 1923 2 Sheets-Sheet 1 Jan- 18 1927 w. .1. RUSDELL PUMP OR MOTOR Filed Jan. l0.. 1923 2 Sheets-Sheet 2 Patented Jan. 18, 1927.

UNITED "s rares FIGB;

r'uivrr on Moron.

Aplucauon inea January 1o, 1923, serial no. entre, and in Great Ainseam January lai'zz.

This invention relates to pumps for-liquid and to motors operated by liquid under head or pressure, both of the type employing tyvo or more buckets or pistons or the like, hereinafter referred to as pistons, and particularly tothe type wherein the liquid flows continuously at substantially uniform velocity.

In the case of a pump, the said pistons are voperated through mechanism from a rotating shaft or part and, in the ease of 4a motor, the shaft is operated by the pistons through mechanism so 'as to rotate.

The construction may be taken to be similar for either pumps or motorsbut reversed in action; it Will therefore only be neceslsary to describe the construction of an fapparatus suitable for a pump; merelyadding that, in the case 'of a motor, mechanically operated valves for liquid are preferable.

-According to the invention the rotating shaft or part is provided With a cam of appropriate shape which Vactuates two or morebell crank levers Which are preferably provided with anti-friction devices, 'such as rollers, Where they engage With the cam; the levers Vare pivoted at substantiallyequal `distances from the axis of rotation of the Ycam andthe pivots are substantially symmetrically arranged with respect to the axis of rotation of the cam. This means that, lWhen there are two bell cranks, a straight line'drawn through the axes of their pivots passes through, or approximately through,

`the axis of rotation of the cam.

vTo impart uniform velocity to the Water, the bucket or piston in contact therewith miistmove withjuniform velocity. Assuming that the `shaft to which the cam is lattached is rotating at a uniform rate, the

cam is so designed that, during that part of the rotation of the shaft which' corresponds with the powerstroke of the piston, forsmall lequal 'movement of the shaft' and cam, the vpiston is caused to move through equal longitudinal distances, thus giving V.equal volumetric displacements and therefore uniform velocity to the Water. Thus, -ifthefpower stroke of the piston corresponds with, say, 110 revolution of the shaft and "cam and it is required that the piston shall move through m `units 4of distance, then for `every l1o rotation ofthe shaft and cam'the pitn amer 'move the cam must be :designed accordingly.

units of distance and satira 'can @an muy @graphie-iiyama out bya competent designer.

By similarly forming thoseparts of the levers which are in contactvvith vthe cam,

the cam operates the levers successively at equal intervals of time 4and..iriparts"equal motion to the levers, thus'fulflling vthe purpose of this invention.

Now according to the positions of the pivots md the lengths and directies jef 1o those arms of the levers which arefin operative connection with the pistfos,`it pssible to impart equal or proportional motion to the pistons, and the lattery may 'be armagma-axial with, er parallel, er incurred 15 to one another, but all being controlled'froni the same cam so as tonglve LA'subst'aritially equal volumetric rates of displacement for corresponding movements `ofthelleviers.

The invention is illustratedin the acooin- 3 panying drawings, Figures 1 to H8, leach figure representing, in section, a pump br Part ofapumpy as V being on `a line la, '2, 1% vvhichfpasses 85 through .the axis of .rfain 26M@ @amig andare at substantially equal distances from this axis.

The arms Llfarid 4b ofthe lrespectives bell cranks have rollersaand bfwhich 'rollon 90 the. @arrlelld` are kept, in Cteitstherwth by suitable means such as by springs `(n ot here shown) tending to for/ce 5 v'and 5* towards `one. another.

i. ri,

The arms 6a and 6b operate, iespectiyely, 95

through links 8?, 8b, :rods "7y and 7 1 vwhich in turn operate the respective pistons;y and 'since the pistons are co-axial, rod 7b is tubular in order that Ythe rod 7a lmay pass through it. As the cam '3 rotates, the ends of `the bell-cranks Which `c`arry 'the rollers are moved outwards and inwards to follow` the profile of the cam, and it Willbe seen that, if the corresponding arms of the bell cranks are equal in length and the rollers are equal in diameter, then the right hand, end of arms 6a and 6b will have exactly equalfmotiom but that movement of the one will coeur halfa revolution'of the cam earlieror later thanthatof the other. The downward strokes of the pistons'are caused by their weight aided by the aforesaid springs.

Gland 9b is required when the level of delivery is above, the level of the upper end of the pump cylinder.

By suitably shaping the cam, it may be arranged that the greater part of the upward strokesof the respective pistons occurs at substantially uniform velocity and that the respective periods of uniform velocity overlap. l

Fig. 2 shows pump rods 7, 7b which are flexible, as for inst-ance ropes or chains, and are connected with the respective arms 6a, 6b by means of arcs in well-,known manner. The downward strokes may be caused solely by the weight of the pistons, in which case the cam would be so shaped as to give the pistons suitable downward acceleration. In the case shown, however, springs give part of t-he downward acceleration, 10LL serving this purpose for the lower piston and l0b for the upper piston. The working barrel ll may be held by its own weight against the lifting tendency of the said springs, or it may be anchored. In the former case a tight joint is made at l2 and, when the barrel requires inspection, it may be lifted together with the pistons by hauling the flexible rodsa and 7b.

Fig. 3 shows a pump, particularly suitable foi" low lift, in which the arms 6a, 6 extend in opposite directions so that the pistons are more easily inspected than in the previous constructions. Since Vthe lateral movement of the outer ends of arms'a and Gb is generally relatively small as ycompared with the length of rods 7 and 7b, the links 8", 8b, together with the guides for the upper ends of the rods, may be eliminated.

, Fig. 4 shows a compact form of pump having co-aiiial pump rods in compression. Fig. 5 is an enlarged view of the cam and levers and the connections of the latter with the pump rods. It will be noted that the links 8a and 8b are of very simple form, not requiring pin joints, and that the bell cranks, being constantly pressed against the cam, can merely be slotted to receive the pivots l, lb, thus greatly facilitating dismounting and assemblage. Springs 10a, and

'10b produce thereturn strokes and take up Wear.

Fig. 6 shows the application of the invention to a wing pump with oscillating pistons. The pistons may be rectangular and oscillate about the pivots la, 1b respectively. As here shown, they perform the functions of the Varms Ga, 6b of the other forms herein described, so thatlinks and rods 8, 8b, 7, 7 are eliminated.

' lIn Fig. 7 the pistons 13a, 13b are shown as integral with the arms 6a, 6b, respectively, and oscillate about the' pivots l? and 1b, whiclrserve'l to guide the pistons andv prevent the weight of the pistons causing friction against the surface of the working barrel. The barrel has open ends, piston 133L may be pulled outdirectly and piston 13h may be pulled out after disconnection of link la".

F ig. 8 illustrates a pump suitable for gritty water. It also shows a case in which the arms G and 6b are of different lengths, equal displacement of liquid by the two pistons 13, 13b being obtained by making the pistons of area inversely proportional to the length of the arms. Inflated pneumatic tubes la, lill permit thel necessary strokes, so that the pump rods 7a, 7 can be operated directly by the arms (it, 6b, additional inflated pneumatic tubes 15a, l5" servi1.' g to prevent leakage past the pump rods.

Three or more bell cranks may be used where a multiplicity of pistons is an adn vantage.

Having thus described the nature of the said invention and the best means I know of car 'ying the same into practical effect, I claim:-

l. Apparatus for forcing or raising liquid and for producing power from liquid under pressure, comprising reciprocating pistons operating in series, a driving shaft, a cam mounted on the said shaft, bell crank levers engaging the said cam and having their engaging arms similar to each other, pivots on which the said levers turn, the said pivots being disposed equidistant from the axis of rotation of the said shaft and symmetrically with respect to the said anis, and an operative connection between the said bell crank levers and the said pistons respectively, tho profile of the said cam being such that, during that part of the rotation of the shaft which corresponds to the power-stroke of the piston, for small equal movement of the shaft and ,cam the piston is moved through equal longitudinal distances, thus giving equal volumetric displacements and therefore uniform velocity to the liquid.

2. Apparatus for forcing or raising liquid and for producing power from liquid un'- der pressure, comprising two reciprocating pistons operating in series, a driving shaft, a cam mounted on the said shaft, two bell crank levers engaging the said cam and having their engaging arms similar to each other, pivots on which the said levers turn, the said pivots being disposed cquidistant from the axis of rotation of the said shaft Vand in the same straight line through the said axis, an operative connection between the said bell'crank levers and the said pistons respectively, the profile of the said cani being such that, during that part ofthe rotation of the shaft which corresponds to the power stroke of the piston, for small equal movement of the shaft and cam the piston is thus giving equal volumetric displacements and therefore uniform velocity to the liquid. q 3. Apparatus for forcing or raising liquid and for producing power from liquid under pressure, comprising two reciprocating pistons coaxial with each other and operating in series, a driving shaft, a cam mounted on the said shaft, bell crank levers, each having one arm engaged with the said cam and the other arm in operative connection with the said pistons respectively, the said other arms being .similar and similarly directed to each other, pivots on which the said levers turn, the said pivots being disposed equidistant from the axis of rotation of the said shaft and in the same .straight line through the said axis, the profile of the said cam being such that, during that part of the rotation of the shaft which corresponds to the power stroke of the piston, for small equal movement of the shaft and cam the piston is moved through equal longitudinal distances, thus giving equal volumetric displacements and therefore uniform velocity to the liquid.

4.. Apparatus for forcing or raising liquid and for producing power from liquid under pressure, comprising two reciprocating pistons operating in series, a driving shaft, a cam mounted on the said shaft, bell crank levers, each having one arm engaged with the said cam and the other arm in operative connection with the said pistons respectively, the said other arms being different and directed differently from each other, pivots on which the .said levers turn, the said pivots being disposed equidistant from the axis of rotation of the said shaft and in the same straight line through the said axis and the profile of the said cam being such that, during that part of the rotation of the shaftv which corresponds to the power stroke of the piston, for small equal movement of the shaft and cam the piston is moved through equal longitudinal distances, thus giving equal volumetric displacements and therefore uniform velocity to the liquid.

5. Apparatus for forcing or raising liquid and for producing power from liquid under pressure, comprising two reciprocating pistons operating in series, a driving shaft, a cam mounted on the said shaft, two bell crank levers each having one arm engaging the said cam and the other arm in operative connection with one of the said pistons, a slot in each of the said levers, pivots constituting the fulcrums of the said levers respectively, the said` pivots engaging in the said slots respectively and being disposed equidistant from the axis of rotation of the said shaft and in the same straight line through the said axis, the said operative connections between the bell crank levers and the said pistons being maintain-ed by pressure of the latter and the profile of the said cam being such that, during that part of the rotation of the shaft which corresponds to the power stroke of the piston, for small equal movement of the shaft and cam the piston is moved through equal longitudinal distances, thus giving equal volumetric displacements and therefore uniform velocity to the liquid.

6. Apparatus for forcing or raising liquid and for producing power from liquid under.

pressure comprising a driving shaft, a cam mounted on the said shaft, two bell crank levers each having one arm engaging with the cam and having the other arm shaped as a piston, the two pistons operating in series, pivots on which the said levers turn, the said pivots being disposed equidistant to the axis of the said shaft and in the same st-raight line through the said axis and the profile of the said cam being such that, during that part of the rotation of the shaft which corresponds to the power stroke of the piston, for small equal movement of the shaft and cam the piston is moved through equal longitudinal distances, thus giving equal volumetric displacements and therefore uniform velocity to the liquid.

7. Apparatus for forcing or raising liquid and for producing power from liquid under pressure, comprising reciprocating pistons of unequal area and operating in series, a .driving shaft, a cam mounted on the said shaft, bell crank levers each having one arm engaging the said cam and the other arms of the said levers being of unequal length, these lengths being in inverse proportion to the areas of the said pistons, pivots on which the said levers turn, the said pivots being disposed equidistant from the axis of rotation of the said shaft and symmetrically with respect to the said axis, an operative connection between those arms of the levers which do not engage the cam and the piston in the sense that the piston ofv smaller area is connected with the longer arm, the profile of the said cam being such that, during that part of the rotation of the shaft which corresponds to the power stroke of the piston, for small equal movement of the shaft and cam the piston is moved through equal longitudinal distances, thus giving equal volumetric displacements and therefore uniform velocity to the liquid.

In testimony whereof I have signed my name to this specification.

WILLIAM JOSEPH RUSDELL. 

